The present invention relates to a device for selecting and engaging gears in an automatic vehicle gearbox.
These devices comprise driving means that may be activated in a first or a second configuration in which they select and engage the gear, respectively, immediately higher or lower than the one engaged when the means were activated.
These devices also comprise a manually operated lever for changing gear and a plurality of pushbuttons or selectors; this lever may be set in a first and in a second position in each of which said driving means are activated respectively in said first and second configuration set forth above; thus, by moving this lever into one of the two said positions, the driver of the vehicle may select and engage the next gear up or down.
In known devices of the type described briefly above, the gear lever normally oscillates on a plane so as to be set in one of the two angular positions set forth above, but may also be made to oscillate on another plane orthogonal to the previous plane so as to bring it into a third position in which the driving means are activated to bring the gear lever into the neutral position.
Furthermore, the device normally comprises a selector, located normally on the dashboard of the vehicle, which may be set to a position in which, when the gear lever is moved into the first or second angular position set forth above, the driving means are activated in a further configuration corresponding to the selection and engagement of the reverse gear.
Devices of the type described in brief above have several drawbacks.
First of all, if the selecting and engaging manoeuvres and the clutch engaging and disengaging manoeuvres are to be performed in conditions other than those in which they are normally performed, or in emergency conditions, the times required by the driving means to automatically perform these manoeuvres are excessively long; an example of these situations is when the driver has to change gear on a vehicle with a heavy load to drive up a steep hill or when, on a downward slope, he requires the braking action of the gears for greater control of the vehicle. Furthermore, in the devices set forth above, the operations required to activate the driving means corresponding to the neutral position or the selection and engagement of the reverse gear are not simple and instinctive, as they require the gear lever to be moved on different planes from the plane on which the lever oscillates for the selection or engagement of a gear or even manual activation of special acceptor selectors.